Liquid fuel burning apparatus



July l, 1941- '.J. R. KIRKPATRICK LIQUID FUEL BURNING APPARATUS 6 Sheets-Sheet 1 Filed April 1S, 1939 :ullllllug INVENTOR,

BY JOPH \R.K112

KPATRI M *Us crc MA- ATTORNEY 5.

July 1, 1941. J. R. KIRKPATRICK LIQUID FUEL BURNING APPARATUS Filed April l5, 1959 6 Sheets-Sheet 2 INVENTOR. JOSEPH R. KIRKPATRICK ATTORNEYS.

July 1, 1941- J. R. KlRKPATl 2,247,689

LIQUID FUEL BURNING APPARATUS Filed April l5, 1939 6 Sheets-Sheet 3 INVENTOR. JOSEPH RKIRKPATRICK `M,MMM

n ATTORNEYJ.

Jui'y 1, 1941.

J. R. KIRKPATRICK LIQUID FUEL BURNING APPARATUS Filed April 15, 1939 6 Sheets-Sheet 4 INVENTOR.

Ms. 1 n m A Am m JOSEPH Il BY July 1 1941- J. R. KlRKPA-rRlcK 2,247,689

LIQUID FIJ-EI.:4 BURNING APPARATUS xFiled April 15, 1939 INVENTOR.

July 1', 1941- .1. R. KIRKPATRICK 2,247,689

LIQUID FUEL BURNING APIARATUS Filed April 15, 1939 6 sheets-sheet 6 INVENTOR. JOSEPH 12.1{1RKm-IRICK.

ATTORNEYS.

Patenied July 1,1941

UNITED STATES PATENT ori-ICE LIQUID FUEL BURNING APPARATUS Joseph R. Kirkpatrick, South' Euclid, Ohio, as-

sgnor to Perfection Stove Company, Cleveland, Ohio, a corporation of Ohio Application Api-i1 15,1939, seria1No.26s,1ss i (cl. 15s-3s) 5 Claims.

This invention pertains to liquid fuel burning apparatus that is especially suitable for use in furnaces of heating systems for houses or other buildings, and Whose operating range includes low and relatively higher fires, and in which, through suitable fuel feeding and governing means, the burner is constantly supplied with fuel-at no time, so long as the apparatus is in operation, with less than enough to sustain operation at low fire, and at other times with sufficient additional fuel to produce higher re.

Customarily, in apparatus ,of the class to which the invention relates, liquid fuel of a rather heavy grade is used, such as that known as fuel oil; and at low fire, which practically amounts to pilot flame, very little fuel is required. For example: in the average size furnace burner, from one-half to one gallon of fuel is fed every twenty-four hours for the purpose of sustaining operation at low re, and this amounts to very considerably less than one drop per second. Consequently, uniform feeding of the fuel at so low a rate presents a problem rendered dimcult by several factors including variation in viscosity of different fuels; .in the differences in viscosity of the same fuel at different temperatures, or the presence of sediment or foreign matter in the fuel. Under any circumstances, and especially those requiring accurate feeding of a very small quantity of fuel, the customary control of the flow by means of orices (as is the case in practically all types of valves) is quite unsatisfactory and unreliable.

It is the fundamental object of my invention to provide liquid fuel burning apparatus of the character referred to in which the fuel, especially that for supplying low or pilot fire, is volumetrically fedthat is to say, is fed in measured quantities. In its present preferred form, the volumetric feeding means comprises one or more dippers. Where only low or pilot re is supplied with fuel by the volumetric feeding means, a single dipper is used, the fuel supply for higher fire being controlled by suitable valve means;l

from the source, and a delivery part leading to the burner that is separated by a barrier from the reservoir part so as to preclude natural flow of the fuel directly from the latter to the former by gravity. A suitable liquid level control maintains a substantiallyconstant fuel level in the reservoir part, and by suitable transfer means, as by the dipper or dippers above mentioned, measured quantities of fuel are transferred from the reservoir part to the delivery part of the system whence the fuel flows by gravity to the burner. A A motor or other appropriate meansdesirably a small electric motor-has suitable driving connection with the dipper or dippers for oscillating the same, the one for supplying fuel to the low or pilot lire being constantly actuated so long as the-apparatus is'in operation.

Another object of the invention is to provide an automatic control by means of which the apparatus is caused to operate under certain conditions at intermediate fire, so to speak, thereby to maintain a given temperature, Within rather close limits, in a space to be heated-as lin a room, apartment or other enclosure-and which, in case the temperature of said space drops below a predetermined value, will act to cause an increase in the fuel supply to" the burner so as to produce a higher fire; and in case the temperature of said space rises above a predetermined value, will function to suspend operation of all but the volumetric feeding means that supplies fuel for low or pilot fire, thereby to reduce the heat output of the apparatus.

A further object is to provide, in an automatically controlled apparatus of the character described, means for effecting delivery of fuel to the burner in sufficient quantity to sustain operation thereof at approximately intermediate fire in case of failure of -the automatic control; for example, by the stoppage or suspension of the supply of current, in case the control system is electrical.

A still further and more limited object of the invention is to provide fuel feeding and governing means in the form of a compact unit that is convenient of incorporation in a liquid fuel burning apparatus and 'is so constructed as to facilitate assembly and installation and that is efficient and reliable in operation.

The foregoing objects,.with other and more limited ones hereinafter appearing, are attained in the embodiments of the invention illustrated in the accompanying drawings wherein Fig. 1 is a diagrammatic representation of a liquid fuel burning apparatus incorporating a form of the invention characterized by a fuel feeding andl governing system in which the fuel is volumetrically fed to the burner in suilicient quantity to sustain operation at low fire, while the supply of additional fuel for producing higher re is valve-controlled; Fig. 2 is a sectional plan of the structural unit embodying the fuel feeding and governing system of the form of the invention shown in Fig. 1, the construction being that employed in practice, and the viewshowing the cover of .the float chamber removed; Fig. 3 is a plan view of the cover of the iioat chamber and the valve actuating means mounted thereon; Fig. 4 is a vertical section through the aforesaid unit on the line 4-4 of Fig. 2; Fig. 5 is a sectional detail of the reservoir, dipper and associated parts of the volumetric -fuel `feed of the aforesaid unit, the slightly offset planes of section being indicated by the line 5,-5 of Fig. 2;

lvvalve 22.

to maintain a constant liquid level in said reservoir part, and a delivery part' that communicates with the burner through the aforesaid conduit ll.

The system C (Fig. 1) includes a float chamber to the bottom of which lthe conduit l0 is connected and with 'which said. conduit communicates through a port -2| .controlled by a A spring 23 tends to lift the valve from its seat, and the valve is closed by a float 24 that is carried by a lever 25, fulcrumed on a pivot pin 26 suitably supported in the valve chamber. The end of thelever remote from the float bears against the head of the valve 22.

Through a conduit 30, the float chamber communicates with a receiving compartment or resv ervoir 3l of a vessel 32, said compartment being Fig. 6 is a sectional detail substantially on the line 6 6 of Fig. 3 and showing the valvesfor controlling the supply of fuel for intermediate and high lires; Fig. '7 is a view similar to Fig. 1

illustrating a form of the invention characterized by a fuel feeding and governing system in which the fuel is supplied to the burner throughout its entire range of normal operation by a multiple volumetric fuel feed comprising a plurality of dippers, and Fig. 8 is a'detail in perspective, with parts broken away, of the multiple volumetric fuel feed of the latter modication.

The installations diagrammatically illustrated in the drawings may be parts of heating systems for dwellings or other buildings and desirably involve-means for automatically controlling the operationof the burner so as to maintain, in the space or apartment heated by the system, a substantially constant temperature within relatively close limits.

According tothe present illustrative embodiments; the burners are of the pot or bowl variety, and in each of the two cases (Figs. 1 and 7) the burner, designated, generally, by the reference character A, comprises a bowl I that is suitably supported with its top wall 2 in spaced relation to the bottom wall 3 of the combustion chamber 4. Said walls have aligned openings shown as surrounded by depending flanges 2a and 3, respectively, that are in concentric, spaced relation to each other and define a slot 5 for the admission of secondary air to the burner bowl, as will hereinafter more fully appear. Primary air is admitted to the bowl through perforations 6 in the peripheral wall of the bowl. A relatively large lightingand cleanout opening is formed in said wall and the same is surrounded by a y radially projecting neck 8 normally closed by a plug 9 shown as having a bayonet joint connection with the neck. The combustion apparatus comprising the bowl I and chamber 4 may be that of a furnace of appropriate type for use in systems of the class above mentioned. For more detailed information on such apparatus, refer- -ence may be had to Letters Patent Nos. 1,944,593, 1,979,865,'1,987,179 and 2,000,884, dated January 23, 1934, November 6, 1934, January 8, 1935, and May '7, 1935, respectively.v

Liquid fuel is supplied to the burner A from a source B (represented as a tank) through a fuel feeding and governing system C (Fig. l) or D (Fig. 7). In each instance, a conduit I0 leads from said source to the system, and a conduit Il leads from the system to the burner, the latter conduit being shown as opening through the bottom wall of the bowl l. Each system involves a reservoir part, to which fuel is supplied through said conduit i0; a liquid level control that tends separated'by a partition 33 from an outlet compartment 34. 1 Said partition constitutes a form of barrier that separates the system C into a reservoir part to which fuel is supplied from the source B, and aidelivery partfrom which fuel flows by gravity to the burner A, as will hereinafter more-fully appear. By the arrangement shown and described, the same liquid level prevails at all times within the float chamber 20 and receiving compartment 3l of the vessel `32, the space thus represented constituting the reservoir part of the system, hereinbefore referred to; and the oat, with the valve 22, forms the liquid level control that governs the elevation of the liquid in said part.

The outlet compartment 34 of the vessel 32 communicates, through a conduit 35, with a passage 36 between the float chamber 20 and a valve casing 3l whose outlet joins the previously mentioned conduit llvthat leads to the burner. Operating within the casing 31 is a so-called metering valve 40 that is adapted to be manually adjusted between full open and closed positions by appropriate means including a stem 4I. The valve 40, shown as having the usual thread connection 42 with the valve casing, is provided with a graduated notch 43 by which the flow through the valve may be accurately controlled when the valve is in any other than full open or closed positions. The outlet compartment 34, conduit 35, passage 36, and valve casing 3l that joins the conduit TI constitute the previously mentionedA delivery part of the fuel feeding and governing system. l.

Direct flow of fuel from the float chamber 20 to the passage 36 is controlled by two valves 45 and 46, shown as tubes or sleeves slidably fitted one within the other, the outer valve being similarly fitted within a valve casing 41 shown as an integral part of the l float chamber. Said valve casing 41 communicates with the interior of the float chamber through a port 43, and with the passage 36 through a port 43. When the inner tubular valve 45 is fully. depressed its lower end shuts olf communication between the valve casing and the float chamber through the port 48. Communication between the valve casing and the port 49 is controlled by the valve 46, the lower end of which is formed with a V notch 50. As will more fully appear hereinafter, the supply of additional fuel to the burner for producing intermediate and high fires is controlled by the valve 46, and when in position to pass the additional quantity necessary to produce intermediate fire only a limited portion of the area of the V notch 50 extends above the bottom edge of the port 49. The descent ofthe valve 46 is limited by a stop, and preferably this stop is adjustable so that the size or volume of the so-called intermediate fire may be varied. According to the present embodiment of the invention, the stop, designated 55, consists of a collar on a stud 56 that is threaded through a part on the valve chamber 20 and is adapted to be locked in any adjusted position by a nut 51. The portion of the stud above the stop 55 extends freely through an aperture in a plate 58 that is suitably fastened to the upper end of the tubular valve 46 and comprises a part of a yoke 60.

The valve 46 has operative connection, through the yoke 60, a link 6|, and a member 62 with the free end of a thermostatic element 63, consisting of a bi-metal strip; and the valve 45 is attached to the free end of a similar thermostatic element 64, through a member 65 and link 66. 'I'he elements or strips 63 and 64 have their inner ends adjustably connected to a standard 66 that rises from the cover 69 of the float chamber 20. Adjustment ofthe strip with respect to the standard is accomplished through screws 15 that pass freely through holes in the standard and in the laterally turned end portions of the elements or strips and are threaded through bars 11, and screws 18 that are threaded through the stand-- ard 68 and bear against the elements or strips in properly spaced relation to the screws 15. By relatively adjusting the` screws 15 and 18 associated with each element, such element may be rocked to vary its normal angular relation to the standard 66 and consequently change the normal positions of the valves 45 and 46.

Suitably attached to the respective thermostatic elements or strips 63 and 64 are electric heaters 80 and 8| in the form of coils of resistance wire; and when said heaters are "cold the elements or strips occupy the positions in which they are shown in full lines in Fig. 1 thereby to retain the valve 45 open and the valve 46 in the position determined by the stop 55-that is, in the position when the minimum portion ofthe area of the notch 50 is uncovered, or above the bottom edge of the port 49.

Supported by the vessel 34 for oscillation upon a pivot 85 is a trough-like bucket or dipper 86. It will be observed that the pivot 85 is above and in the region of the partition 33, and that the adjacent open end of the dipper is thus disposed over the outlet compartment 34. The opposite, closed end of the dipper is adapted to be raised and lowered between a position adiacent the bottom of the compartment 3| and a position above the horizontal plane of the pivoted end of the dipper by a crank 81 to the pin of which the free end of the dipper is attachedthrough a'connecting rod or link 88. The crank 81 is secured to the shaft 89 of a small electric motor 90 that is suitably supported, as being fastened to the side of the vessel 32.

The fuel feeding and governing system is desirably automatically controlled by an electric system including a transformer 95 and a so-called room thermostat 96 that is subjected to the temperature of the space that yis heated by the apparatus. The two legs of a'main or house circuit of 110 volts, for example, are represented by conductors and |0| that are connected, respectively, to the opposite ends of the primary winding 95a of the transformer. The conductor |00 includes a switch |02, and a branch of said main or house circuit, represented by conductors |00l and I0 I, leads to the previously mentioned motor 90.

the transformer has connection, through a conductor |04, with the movable contact element of the room thermostat 96, such element swinging in response to changes in temperature, as is well understood by those familiar with control systems of the kind in question. The opposite side of the secondary winding 95b is connected,

through a conductor |06, with one end of the heaters 80 and 8| that are attached to the thermostatic elements or strips 63 and 64, respectively. The opposite end of the heater 80 is connected, through a conductor |01, with the con- One side of the secondary winding 95b of 75 tact point |08 of the room thermostat, while the opposite contact point |09 of said thermostat has connection, through the conductor ||0, with the corresponding end of the heater 8|.

From the source B, liquid fuel is conveyed by the conduit I0 to the reservoir part of the system comprised of the float chamber 20, conduit 30, and receiving compartment 3| of the vessel 32; and, under the influence of the liquid level control comprising the float 24 and valve 22, the fuel stands at approximately the level represented by the dot-and-dash lines a, a of Fig. 1. This level is well below the top of the partition 33, wherefore fuel is prevented from gravitating from the compartment 3| to the outlet compartment 34, and

thence through conduit 35, etc., to the burner. With the valve 45 normally in open position, as illustrated in the drawings, fuel is permitted to flow, under restraint of the valve 46, from the iioat chamber 20 through ports 48 and 49, passage 36, valve casing 31 and conduit to the burner A, it being assumed, of course, that the metering valve 40 is open to a greater or less extent.

With the switch |02 closed, current is supplied to the transformer 95 and to the motor 90. Under the constant action of the motor 90 the dipper 8,6 will be oscillated on its pivot to intermittently transfer measured quantities of fuel from the reservoir part of the system-or more specifically, from the compartment 3|-to the delivery part of the system-including the outlet compartment 34-from where the fuel will flow by gravity to the burner. The fuel thus volumetrically fed from the reservoir part of the system to the burner in sufficient quantity to sustain operation at low fire, is augmented by the fuel that normally passes valves 45 and 46 from the float chamber to the passage 36, the aggregate amount of fuel thus being supplied to the burner being suicient to maintain operation at what has been termed intermediate fre. In other words, with the system operating under normal conditions, the lire is kept at intermediate stage. Under these circumstances the apparatus produces enough heat to maintain, against the inliuence of a lower outside temperature, a room or space temperature within a predetermined range for which vthe thermostat 96 is set, it being understood that said thermostat is of the customary form capable of adjustment to vary the value 'and range of the controlled temperature.

When the room or space temperature rises above the aforesaid predetermined range, the element |05 will swing to the left into engagement with contact point |09 thereby to close the circuit that includes the secondary winding of the transformer and the heater 8|; and when the elevated temperature of the energized heater 8| acts upon the thermostatic element or strip 64 it will cause said element or strip to warp to the position indicated by dotted lines in Fig. 1 thereby to depress and close the valve 45 shutting oil' the ow of fuel from the float chamber directly vwherein it retains the valve 45 open, allowing the burner to proceed at intermediate flre.

Under a drop in room temperature'suilicient to cause the element |05 of the room thermostat to swing over into engagement with the contact |08, the circuit including the secondary winding of the transformer and the heater 80 will be closed, and when the elevated temperature of the energized heater acts upon the thermostatic element or strip 63 it will cause the latter to assume the position shown in dotted lines in Fig, 1 thereby, through the link 6| and yoke 60, to lift the valve 46 so as to increase the fiow of fuel from the float chamber through the ports 40 and 49 to the passage 36 and thence to the burner, causing the burner to operate at high fire, and under the influence of the additional heat generated by the apparatus the temperature affecting 'the room thermostat 96 will be raised enough to cause the element |05 to resume neutral position and open the circuit to the heater 80, after which the system will resume normal operation with the burner operating at intermediate fire.

Attention is directed to the fact that, in the form of the invention above described, should the electric power fail from any cause, resulting in the stopping of the motor 90 and the dipper 86 so that volumetric feeding of the fuel ceases, a fioW of fuel in sufficient amount to sustain operation of the burner at relatively low fire will be insured by reason of the open position occupied under such circumstances by the valves 45 and 46. In other Words, upon failure of the power-the same as when the room thermostat 96 is in neu- Gral condition, and the circuits controlled thereby are open-the volumetric feeding means is by-passed through the valve controlled ports 48 and 49.

In a practical application of the invention according to the form disclosed in Fig. 1, the elements of the fuel feeding and governing system C assume the physical form and relation illustrated in Figs. 2 to 6; and the corresponding parts of the system appearing in Fig. 1 and in Figs. 2 to 6 are designated by the same reference numerals. l

As shown in Figs. 2 and 4, the iioat chamber 20, through a suitable number of laterally ex` f tending bosses ||5, is secured to a wall ||6 of a supporting structure designated, generally, ||1,

the connection between each boss ||5` and said wall ||6 being made bya screw ||8. A relatively large hollow boss |20 extends laterally` from the float chamber into an opening |2| of the wall ||6, and in the plane of said wall has a leak-proof connection withA a. ported arm |22 of a casting that includes, as an integral part thereof, the previously mentioned vessel 32 (Fig. 5). To the opposite side of the arm |22 is fastened, with a leak-proof joint, the inlet boss of the previously mentioned valve casing 31. These three units are bound together by screws |24 that pass through aligned apertures in the valve casing 31 and in the arm |22, and are threaded into tapped holes in the boss |20 of the valve chamber. The motor 90 is shown (Figs. 2 and 5) as fastened, by screws |25, to one of the side walls of the vessel 32, and the electrical conductors through which current is supplied to the motor is sheathed in a conduit |26 having a terminal elbow fitting |21, fastened to a bracket |28 that extends laterally from and is integral with the vessel 32. The pivot 85 of the dipper 86 is supported by and between the opposite branches of a U-shaped member |30, said branches being bifurated at their lower ends for engagement over the upper edge ofthe partition 33, as clearly shown in Fig. 5. The member |30 is supported by a screw |3| from an overhanging bracket |32 that is fastened, as by means of screws |33, to the flanged top of the adjacent end wall of the vessel 32. A spring |34 surrounds the screw |3| and is interposed between the member |3 0 and the overhanging bracket |32. The screw |36, being free in the bracket and threaded into the member |30, provides a convenient means of adjusting the member vertically thereby to alter the elevation of the frontend of the dipper 86 and thus change its feeding capacity.

As indicated in Fig. 4, the registering openings of the inlet extension of the valve casing 31, arm |22 and boss |20 constitute the previously mentioned passageway 36; and the bore in .the arm. |22 through which said passageway cornmunicates with the outlet compartment 36 of the vessel 32 corresponds to the conduit 35 and accordingly is designated by the same reference numeral.

The electrical connections to the heaters 00 and 8| are, in practice, made through binding posts |35 (Figs. 3 and 4), that are carried by a shelf |36 of insulating material, suitably fastened to and supported from the standard 68 that rises from the cover 69 of the float chamber, the cover, with the parts mounted thereon, being shown in Fig. 3 as removed from the chamber.

In the fuellfeeding and governing system D, shown diagrammatically in Fig. 7, the. fuel is conducted from the source B through the conduit |0 to a float chamber |40, said conduit communieating with the chamber through a port |4|. The passage of fuel through said port is controlled by a valve |42 that is depressed and closed by a float |43 through the intervention of a lever |44, fulcrumed on a pivot pin |45' that is fixed with respect to the float chamber. A spring |46 tends to open the valve inv opposition to the action of the float. By this control means, the level of liquid in the reservoir part of the system is maintained substantially at the elevation indicated by the dot-and-dash line aa. A

What has been referred to as the reservoir part of the system includes, also, the receiving compartment or reservoir |50 of a vessel |5|I said compartment being ,separated from an outlet the vessel |5| is communicatively connected to the burner A through th'e conduit and a bypass between the reservoir part of the systemspecifically, conduit |55--and the delivery part of the systemis provided by a conduit |51 that contains valve means comprising a casing |58 and a valve member |59, the latter being in the form of a tube, similar to the valve 46 of the previously described embodiment of the invention, and having a V-notch |60 at its lower end in the region of the diaphragm |6| of the valve casing. The casing includes a sleeve wherein the stem portion of the valve member is housed and whose Aopen top is a substantial distance above the maximum liquid level in the system. The valve is normally held in closed position by a solenoid |65, while a spring |66 tends to shift the valve to open position when the solenoid is de-energized, these actuating elements being shown as operatively connected to the valve through the medium of a bell crank |61. The full open position of the valve is determined by an adjustable stop |68.

Supported by the vessel a material distance above the partition |53 is a channel bar |10 (Fig. 8), through square holes in the bottom flange of which are guided for vertical adjustment hangers |1|. The hangers, being square in cross section and of a size to slidably fit the holes, are adjustably supported by screws |12 that are threaded into axial recesses in the upper. ends of the hangers and extend freely through holes in the top flange of the bar |10. Pivotally connected to the lower ends of the hangers |1| are the trough-like buckets or dippers |15, |16 and |11, the size and capacity of the last mentioned dipper beingconsiderably greater than the dipper |16, while the dipper |16 is of somewhat greater capacity than the dipper |15. The dipper |15 corresponds in purpose and action to the dipper 86 of the previously described embodiment of the invention, serving as it does to supply fuel to the burner in suflicient quantity to sustain operation at low or pilot fire. As will more fully appear hereinafter, the dipper |16 supplies the additional fuel necessary to sustain operation of the burner at intermediate fire, while the dipper |11 further increases the fuel supply to that necessary to cause the burner to operate at high fire.

Shown as supported by and exteriorly of an upwardly extended portion of one of the side Walls of the vessel |5| is an electricmotor |80 whose drive shaft |8| is extended through an aperture in the Wall extension and has fastened to it a pinion |82 that meshes with a spur gear |83, journaled on a stud |84 that extends inwardly from said wall extension. A crank pin |85 on the gear |83 is operatively connected to the dipper |15, near the free end of the latter, by a connecting rod or link |86. Fastened to the outer end of the motor shaft |8|, beyond the pinion |82, is a double crank |81, the diametrically opposed pins whereof are designated |88 and |89. These respective crank pins extend freely through slots in connecting rods or links |90 and |9|, the former being attached to the bucket |16 and the latter to the bucket |11.

Secured to and depending from an overhanging portion |94 of the upwardly extended end wall of the vessel |5| are thermostatic elements orIbi-Inetal strips |95 and |96, by the lower free ends of which are carried latch members |91 and |98, respectively, for holding engagement with extensions 200 and 20| on the respective dippers |16 and |11. Electric heaters 203 and 204, in the nature of resistance coils, are suitably attached to the respective thermostatic elements or strips |95 and |96. AWhen the thermostatic elements or strips are cold, so to speak, they occupy the positions indicated in the drawings, element |96 being in a 'position to cause the latch member |98 thereof to engage beneath the extension 20| and sustain the dipper |11 in elevated position; while the element or strip |95 is normally in a position to retain the latch member |91 beyond reach of the extension 200 of dipper |16.

'Ihe electric circuit of the automatic control system for the apparatus-includes a transformer 2|0, and a room thermostat 2| The two legs of the main or house circuit of 110 volts, for example, are represented by the conductors 2|2 and 2|3, the former including a switch 2|4. This circuit also includes the winding of the previously mentioned solenoid |65. One branch of the main circuit, represented by conductors 2|2a and 2|3, includes the primary winding 2 l0a of the transformer 210, while a secondbranch, constituted of conductors 2|2b and 2|3b, leads to the motor |80. One side of the secondary winding 2 0b of the transformer is connected, through a conductor 2|5, with the movable contact element 2 6 of the room thermostat, while the other side of said winding has connection, through the conductor 2| 1, with the heaters 203 and 204.- The former heater is placed in circuit, through a conductor 2|8, with the contact 2|9 of the room thermostat, while contact 220 thereof is connected, through the conductor 22|, with the heater 204.

The burner, under given conditions .which may be regarded as normal, operates on fuel supplied by the two clippers |15 and |16, the heat produced by the apparatus under these circumstances being sufficient to maintain a room temperature of the desired range, under the influence of which the movable contact element 2|6 of the room thermostat remains in neutral position. Should the room temperature rise beyond the predetermined range, the movable contact element 2|6 will swing to the left and engage contact 2|9, closing the circuit to the heater 203 'and under the influence of the energized heater the thermostatic element204 will warp in the direction to bring the latch member |91 into the path of the extension 200 thereby to retain the dipper |16 in inactive, elevated position while the crank pins |88 and |89 play idly within the slots in the connecting rods or links |90 and |9|.` This leaves only the dipper |15 in operation, and this will supply sufficient fuel to the burner to sustain operation thereof at low fire. Under these circumstances and the influence of a relatively lower outside temperature, the room temperature will drop, causing the movable element 2|6 to withdraw from the contact 2|9, thereby to interrupt the supply of current to the heater 203, allowing the thermostatic element 204 to cool and withdraw the latch member |91 from the extension 200, thus throwing the dipper |16 back into operation.

In the event the outside temperature continues to fall, similarly affecting the room temperature sufliciently to cause the movable contact element 2|6 of the room thermostat to swing over into engagement with contact 220, a circuit will be established through heater 204, causing it to warp the thermostatic element or bi-metal strip |96 in a direction to withdraw the latch member |98 from holding engagement with the extension 20|, freeing the dipper|11 so that it may be oscillated through the action of the crank |89, thereby to increase the fuel supply and cause the burner to operate at high fire, this condition continuing until the temperature affecting the room thermostat has risen to within the aforesaid predeter-` mined range, under which circumstances the contact element 2|6 will withdraw from contact 220, opening the circuit to the heater 204 so that the thermostatic element or strip |96 may cool and resume, its former position wherein the latch member |98 engages the extension 20| and retains the dipper |11 elevated and out of operation.

Should the electric circuit that supplies current to the automatic control system fail from any cause, thereby to de-energize the motor |80 and throw the fuel feeding and governing system out of commission, the solenoid |65 will likewise be de-energized, whereupon the spring |66 will open the emergency valve. permitting a practical amount of fuel to by-pass the multiple volumetric feed comprising the buckets |15, |16 and |11 and sustain operation of the burner until the difficulty is rectified and the system 'returned to normal operation. 'I'hrough the adjustable stop |68 the emergency valve |59 may be set to feed fuel in sufficient quantity to sustain operation of the burner at a stage equivalent to intermediate iire.

Attention is called to the fact that the tops of the valve casings 31, l1 and |58 are a substantial distance above the maximum liquid level in the systems of which they form parts, wherefore 'stumng boxes or other seals are rendered unnecessary and freedom of action of the valves is assured.

Having Vthus described my invention, what l claim is:

l. In combination, a vessel havlnga projecting arm provided witha transverse horizontal through passage and a port establishing communication between said passage and the interior of the vessel so arranged that liquid may gravitate from the vessel to said passage, a liquid level control means including a chamber having a lateral hollow boss joined to one side of said arm with its opening communicating with said passage, a valve casing whose inlet branch is joined to the opposite side of said arm in communication with said passage, a partition dividing the vessel into a receiving compartment and a delivery com-1 partment with the latter of which the aforesaid port communicates, the partition extending from the bottom of the vessel to above the maximumv liquid level therein, communicative connections between the chamber of the liquid level control means and said receiving compartment so arranged that the same liquid'level prevails in both, means for transferring measured quantities of liquid from the receiving compartment to the delivery compartment, and valve means through which communication is established and controlled between said chamber and the aforesaid passage. t

2. In combination, a liquid fuel burner, a source of liquid fuel supply,` a fuel feeding system through which said source communicates with said burner, a barrier separating said system into a reservoir part-to. which fuel flows from said source and a delivery part from which fuel flows to the burner, power operated means acting to perlodcally transfer measured amounts of fuel from the reservoir part past said barrier to the delivery part in suflicient quantity to sustain operation of the burner at low fire, communicative connections including a valve casing'interposed between said source and said burner and by-passing said barrier, a pair of valve members operable within said casing and cooperating to control the passage of fuel therethrough, said valve members being movable to three different relative positions in the first of which the passage through the valve casing is closed, in the second of which the passage through the valve casing is partially open, and in the third of which said passage is entirely open, and thermostatically controlled means for moving said valve members.

3. In combination, a liquid fuel burner 'whose operating range includes low', intermediate and high fires, a source of liquid' fuel supply, a fuel feeding system, a barrier separating said system into a reservoir part to which fuel iiows from the source and a delivery part from which fuel flows to the burner, power operated means acting to periodically transfer measured amounts of fuel from the reservoir part past the barrier to the delivery part in suiiicient quantity to sustain operation of the burner at low iire, further means for effecting delivery of additional fuel from the source to the burner and capable of two conditions in the first of which it adds enough fuel to produce intermediate fire, and in the second of which it further increases the fuel supply thereby to produce high fire, an automatic control therefor including thermostatic means subjected to the temperature of the space heated by said burner, the said further means being in said first condition and said thermostatic means being in neutral condition when the temperature of said space is within a given range, operative connections between the thermostatic means and the said further means whereby, when the temperature of said space rises above said given range, it will cause said further means to become inactive and, whenr the temperature of said space drops below said given range, it will cause the said further means to assiune second condition, and manually adjustable valve means interposed between said source and said burner to limit the maximum quantity of fuel that can pass from said source to said burner.

4. In combination, a liquid fuel burner whose operating range includes low, intermediate and high fires, a source of liquid fuel supply, a fuel feeding system including two branchesvthrough which said source communicates with the burner, means acting to volumetrically feed fuel through Y one of said branches in suiiicient quantity to sustain operation of the burner at low iire, a valve casing constituting a part of the other branch, two valve members within said casing cooperating to control the passage of fuel through the casing, two thennosensitive elements each operatively connected to one of said valve members for imparting movement thereto as said element is affected by changes in tempera-ture, two electric heaters each in intimate heat exchanging relation to one of said thermosensitive elements, a

thermostatic switch subjected to the'temperature of the space heated by the burner, electric circuits'including said heaters and switch, said valve members being so related and adjusted that whenneither heater is energized the valve members will occupy positions permitting a quantity of fuel to iiow through the valve casing which, with that member to assume a position in which the passage through the valve casing is fully opened, and manually adjustable valve means interposed between said source and said burner to limit the maximum quantity of fuel that can pass from said source to said burner.

5. In combination, a liquid fuel burner, asource of liquid fuel supply, a fuel feeding system through which said source communicates with the burner, the same comprising means acting to volumetrically feed fuel from said source to said burner in sufficient quantity to sustain operation of the burner at low fire, a valve casing interposed.

between said source and said burner in parallel with said volumetric fuel feeding means, a pair of valve members reciprocable within said casing and cooperating to control the passage of fuel therethrough, two thermosensitive elements each operatively connected toone of said valve members for imparting reciprocatory movement thereto when said element is affected by changes in temperature, two electric heaters each in intimate heat exchanging relation to one of said thermosensitive elements, a thermostatic switch subjected to the temperature of the space heated .being arranged to cause the corresponding valve member to close the passage through the valve casing when the heater associated therewith is energized, the other thermosensitive element being so arranged that when the heater associated therewith is energized the corresponding valve member will be moved to a position in which the passage through the valve casing will be fully opened, and manually adjustable Valve means interposed between said source and said burner to limit the maximum quantity of fuel which can pass from said source to said burner.

JOSEPH R. KIRKPATRIC'K. 

